Rack and pinions are used for lifting mechanisms (vertical movement), horizontal motion, positioning mechanisms, stoppers and to permit the synchronous rotation of several shafts generally industrial machinery. However, also, they are found in steering systems to improve the direction of vehicles. The features of rack and Spur Gear Rack pinion systems in steering are as follows: simple structure, high rigidity, small and lightweight, and exceptional responsiveness. With this system, the pinion, mounted to the steering shaft, is definitely meshed with a steering rack to transmit rotary motion laterlly (switching it to linear motion) to ensure that you can control the wheel. Furthermore, rack and pinions are used for various other purposes, such as toys and lateral slide gates.
As a mechanical component to transfer rotary into linear motion, gear racks are often in comparison to ball screws. There are pros and cons for using racks instead of ball screws. The advantages of a gear rack are its mechanical simplicity, huge load carrying capacity, no limit to the length, etc. One drawback though is the backlash. The advantages of a ball screw will be the high precision and lower backlash while its shortcomings are the limit in size due to deflection.
There are applications where in fact the gear rack is stationary, as the pinion traverses and others where the pinion rotates upon a fixed axis while the gear rack moves. The previous is used widely in conveying systems as the latter can be utilized in extrusion systems and lifting/lowering applications.
To provide many variants of rack and pinion, KHK has many types of gear racks in share. If the application takes a long size requiring multiple gear racks in series, we have racks with the tooth forms correctly configured at the ends. They are described as “equipment racks with machined ends”. When a gear rack is produced, the tooth cutting process and the heat treatment process can cause it to try & walk out true. We are able to control this with special presses & remedial processes.